Submission #572235

#	Time	Username	Problem	Language	Result	Execution time	Memory
572235		hoanghq2004	Paths (BOI18_paths)	C++14	100 / 100	347 ms	59612 KiB

paths

#include <bits/stdc++.h>

using namespace std;

int n, m, k;
int c[300010];
int f[300010][1 << 5];
vector <int> adj[300010];
long long res;

int main() {
    ios_base :: sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    cin >> n >> m >> k;
    for (int i = 1; i <= n; ++i) {
        cin >> c[i];
        --c[i];
    }
    for (int i = 1; i <= m; ++i) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    for (int mask = 1; mask < (1 << k); ++mask) {
        if (__builtin_popcount(mask) == 1) {
            int cl = __builtin_ctz(mask);
            for (int u = 1; u <= n; ++u)
                if (cl == c[u]) f[u][mask] = 1;
        } else {
            for (int u = 1; u <= n; ++u) {
                if (!((mask >> c[u]) & 1)) continue;
                for (auto v: adj[u]) {
                    if (c[u] == c[v]) continue;
                    f[u][mask] += f[v][mask ^ (1 << c[u])];
                }
            }
        }
    }
    for (int mask = 1; mask < (1 << k); ++mask) {
        if (__builtin_popcount(mask) == 1) continue;
        for (int u = 1; u <= n; ++u) res += f[u][mask];
    }
    cout << res;
}

• Subtask 1: 23 / 23
• Subtask 2: 20 / 20
• Subtask 3: 27 / 27
• Subtask 4: 30 / 30